The present invention relates to a machine for compacting and cutting residual material, in particular for scrap metal.
Scrap compacting and cutting machines are known which generally comprise a containment box for the material to be compacted having appropriate means for the advancement of the material toward cutting means usually consisting of guillotine or scissor shears. The containment box, which generally has a horizontally arranged substantially parallelepipedal configuration, is provided with means for compacting the material so as to obtain for the scrap, which is intrinsically non-uniform and bulky, the required density before it undergoes the cutting action of the shears.
In known machines the material is compacted by means of one or more devices which act in sequence on the material, affecting, for each sequence, a volume of material which corresponds to the lengthwise extension of the containment box, i.e. to its extension in a direction parallel to the direction of advancement of the material. After the material has been compacted and has assumed the configuration of a long parallelepiped, it is pushed so as to advance with intermittent motion through the cutting inlet of the shears by means of a longitudinal pusher which is generally actuated by means of a fluid actuated cylinder.
Due to the fact that the compaction affects large surfaces of material and requires considerable forces, such known types of machines have heavy and expensive structures. Furthermore, the longitudinal advancement of the compacted material, performed by means of a fluid actuated cylinder with a considerable stroke, also significantly affects the production costs of these machines.
In other kinds of machines, the material is compacted in a limited region of the material containment box, in a transverse direction with respect to its advancement, immediately upstream of the shears. Simultaneously with the compacting action performed by the presser element, a movable wall pivoted to said presser element provides a progressive compression of the material along the entire containment box. The advancement motion of the material toward the cutting inlet of the shears is obtained by gravity, by virtue of the fact that the containment box is appropriately inclined in these machines.
Though they partially solve the problems of the preceding machines, even these known types of machine have some disadvantages, mainly due to the inclined arrangement of the containment box which is penalizing from the point of view of installation. The inclined arrangement in fact implies considerable loading heights for the material and an excessively low expulsion thereof after cutting, with expensive lifting installations. Movable machines of this kind are furthermore troublesome to provide.
Another disadvantage is that heavy structures for the containment and compression of the material are in any case required; said structures are linked to the use of the movable wall which acts substantially on the entire length of the containment box.